<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <style>
      body {
        background-color: #3c6382;
        width: 100vw;
        height: 100vh;
        margin: 0;
        padding: 0;
      }
      :root {
        font-size: 14px;
      }

      main {
        display: flex;
        flex-direction: column;
        align-items: center;
      }
      div {
        width: 50px;
        height: 50px;
        border-radius: 50%;
        background-color: orange;
        animation-name: ball;
        animation-duration: 2s;
        animation-iteration-count: infinite;
        animation-direction: alternate;
      }
      section {
        width: 200px;
        height: 10px;
        border-radius: 50%;
        background-color: #000;
        position: absolute;
        bottom: 50px;
        transform: scale(1);
        animation-name: ball-shadow;
        animation-duration: 2s;
        animation-iteration-count: infinite;
        animation-direction: alternate;
      }
      @keyframes ball {
        to {
          transform: translateY(84vh);
        }
      }
      @keyframes ball-shadow {
        to {
          transform: scale(0.1);
          filter: blur(10px);
        }
      }
    </style>
    <main>
      <div></div>
      <section></section>
    </main>
  </body>
</html>
